ProgramNode(0...18)( [], StatementsNode(0...18)( [CallOperatorWriteNode(0...18)( CallNode(0...9)( CallNode(0...3)(nil, nil, (0...3), nil, nil, nil, nil, 2, "foo"), nil, (3...9), (3...4), ArgumentsNode(4...8)([IntegerNode(4...5)(), IntegerNode(7...8)()]), (8...9), nil, 0, "[]=" ), (10...12), CallNode(13...18)( nil, nil, (13...14), nil, ArgumentsNode(15...18)( [CallNode(15...18)( nil, nil, (15...18), nil, nil, nil, nil, 2, "foo" )] ), nil, nil, 0, "m" ), :+ )] ) )